This application claims the priority of German patent document 101 00 899.6 filed 11 Jan. 2001 (PCT International Application PCT/EP01/15244), the disclosure of which is expressly incorporated by reference herein.
The invention relates to a wheel cover for a vehicle wheel having a holding device that is activated by laterally pressing the appropriately positioned wheel cover onto the wheel, and thereby fixes the wheel cover on the wheel body. European Patent Document-EP-0 310 777 A1 and German Patent Document DE-OS 27 45 072 disclose assemblies of the generic type.
Various configurations are known for vehicle wheel covers, particularly for passenger cars. Such wheel covers must be relatively easy to fasten on the wheels, and removable just as easily when a wheel change is to take place. However, during a conventional driving operation, the wheel cover must be held securely and in a captive manner on the vehicle wheel.
The most common type of fastening is a snap-type connection which usually has several holding tongues with holding noses that reach behind a detent shoulder or the like. Normally, the holding tongues are situated on the wheel cover while the detent shoulder or the like is provided on the vehicle wheel or the so-called wheel body.
While these known wheel covers can be fitted relatively easily on the wheel body, specifically by a more or less strong lateral pressing-on, removal is virtually impossible except by using a suitable tool. As a result, wheel covers are often levered off the wheel body using a screwdriver, so that both the wheel body and the wheel cover may be damaged.
One object of the present invention is to provide a wheel cover which has a holding device that is easy mountable and removable (demountable). In particular, the wheel cover should be removable without a tool.
This and other objects and advantages are achieved by the wheel cover according to the invention, in which the holding device is deactivated by a second pressing-on in the same direction (with respect to the mounting direction) of the wheel cover, so that the wheel cover can easily be removed from the wheel body.
According to the invention, the same action or movement which is carried out for mounting the wheel cover (which—as known and explained—can be carried out without a tool) can also be implemented for the demounting or removal in that the wheel cover is again pressed against the wheel body.
This will then operate similarly to a ball point pen, where, as a result of a pressing of the operating button in the same direction, the refill can be moved out of the pen and can be moved back into it. Similarly, according to the invention, a wheel cover of a vehicle wheel can not only be mounted in a simple manner, but can also be removed just as easily.
In a preferred embodiment, the holding device consists of a connecting link path as well as of a detent pin guided therein (during the mounting of the cover plate). One of these elements is assigned to the wheel body and the other being assigned to the wheel cover. When the wheel cover is placed on the wheel body, the free end of the detent pin is guided in the connecting link path such that, when the wheel cover is pressed on a first time, its reaches a detent position in the connecting link path, the wheel cover is first held firmly on the wheel body. When, during another pressing-on of the wheel cover, the free end of the detent pin is changed from this detent position into a connecting link path section, by way of which the detent pin is moved out of the connecting link path; the wheel cover can then simply be lifted off the wheel body. This pressing-on of the wheel cover may take place with or without the aid of additional auxiliary devices.
If the mounted wheel cover can be pressed against the wheel body only after overcoming a spring force, it is ensured that, without the application of such a force, the detent pin remains in the detent position with its free end, so that, during normal driving of the vehicle the wheel cover cannot detach itself independently and then be lost. Furthermore, the force necessary to overcome the spring force may have the effect that, when the wheel cover is pressed on again, the detent pin with its free end will really move from the detent position of the connecting link path into the desired connecting link section leading out of the connecting link path. Finally, the latter movement is also promoted by the spring force which had to be overcome previously.
In this context, it should be pointed out that an independent spring element may be used to provide this spring force; such a spring can-be arranged at an appropriate location between the wheel cover and the wheel body and may be constructed, for example, as a coil pressure spring. In an advantageous combination of functions, however, the wheel cover itself may be constructed to be elastic—for example, in the form of a membrane—, and thereby act as a quasi cup spring. In this case, the wheel cover can be supported at least in sections of its circumference on the wheel body while the holding device is provided, for example, in the center of the wheel cover or at other circumferential sections, with such an arrangement it is necessary that, in the last-mentioned area (or possibly in several areas), a desired relative movement be possible between the wheel cover and the wheel body.
If the detent pin is fastened to the wheel cover, the above-mentioned connecting link path is assigned to the vehicle wheel or wheel body. In order to be able to use essentially conventional wheel bodies, the connecting link path can be provided in a separate component (in particular, a special so-called wheel hub insert), which can be inserted into the wheel body. In this case, it is structurally simpler to place a connecting link path in such a component than to mount the so-called detent pin there. The latter can be mounted in a simpler manner (and also protected, for example, by means of a so-called ring segment extension) on the interior side of the wheel cover facing the wheel body. In addition, it is advantageous for the fastening of the detent pin on the wheel cover and/or the detent pin itself to be at least slightly flexible, so that the detent pin with its free end can optimally follow the connecting link path which (with a view to the desired function) necessarily extends in a curved manner.
It is of course necessary to fasten the above-mentioned additional separate component, specifically the wheel hub insert, in an appropriate manner on the vehicle wheel or on its so-called wheel body. This can be done in a particularly simple manner when the wheel hub insert is held in the wheel body by means of at least slightly flexible holding noses, so that, if necessary, a simple exchange of the wheel hub insert will then be possible, if this should be required. To secure such a connection between the wheel hub insert and the wheel cover, the latter may have a so-called ring segment extension on its side facing the wheel body. In the assembled condition, this ring segment extension prevents a movement of the holding noses releasing the wheel hub insert with respect to the wheel body. In this case, such a ring segment extension can also assume a second function, specifically guiding or centering the wheel cover with respect to the wheel body or the wheel hub insert during the assembly.
A single holding device according to the invention (consisting of a detent pin and a connecting link path) may be sufficient. For more secure fastening as well as secure mounting (also under aspects of symmetry), two preferably diametrically opposite detent pins may be provided together with connecting link paths which are assigned to them.
When the most unfavorable circumstances coincide, a wheel cover according to the invention can be removed relatively easily by an unauthorized person (or even by a lateral stone throw from the wheel body) if, as indicated above, for removal purposes, the wheel cover need only be pressed against the wheel body and displaced by a certain distance with respect to the wheel body. In order to prevent such an event, according to an advantageous embodiment of the invention, the wheel cover can be provided with a securing element which can be overcome only in the case of a precise contact pressure and which, when the wheel cover is not precisely pressed on, will prevent displacement of the wheel cover to such an extent that it can easily be removed from the wheel body.
For the latter purpose, a so-called “blocking device” or the like may therefore be provided, which prevents an unauthorized or unintended removal of the wheel cover. On the one hand, this “blocking device” in the form of a suitable securing device according to the invention should be bridgeable relatively easily and particularly without a special tool. These requirements can be met relatively easily by requiring that the pressing-on of the wheel cover takes place in a very special manner in order to be successful; that is, in order to be able to easily remove the wheel cover after the pressing-on with a slight displacement from the wheel body. The latter requires the release of a holding device between the wheel cover and the wheel body by displacement of the wheel cover. Such release should take place only if, during the pressing onto the wheel body, the wheel cover was displaced by a certain minimal distance with respect to the wheel body. If the securing element according to the invention prevents the wheel cover from being displaced by the specified minimum distance relative to the wheel body in the event of a faulty (that is, not precise) pressing-on of the wheel cover, wheel cover also cannot be removed from the wheel body, because the above-mentioned holding device will not be released.
The securing element according to the invention may incorporate various operating principles. Preferably, two components, of which one is fastened to the wheel cover and the other is finally fastened to the wheel body, can then always hook into one another when the wheel cover is not pressed in a precise manner against the wheel body. Such interlocking (which is to be understood in the broadest sense) can take place in a form-locking and/or frictionally engaged manner. Frictional engagement can be utilized in a simple fashion by constructing the securing element as a pair of fitting elements; in that case a first fitting element (which, for visual as well as functional reasons, is provided on the side of the wheel cover facing the wheel body and is aligned essentially perpendicularly with respect to that side) can be introduced with a tight fit into a second fitting element finally fastened in or on the wheel body.
Such precise pressing-on of the wheel cover, which permits a displacement of the wheel cover to such an extent that the holding device between the wheel cover and the wheel body is deactivated, may require, for example, that the wheel cover be pressed on precisely perpendicularly to the wheel plane or the wheel cover plane; that is, exactly in the direction of wheel axis. This can be achieved either by requiring that the (preferably circular) wheel cover (mounted, as customary, concentrically with respect to the wheel) be pressed exactly in its (circular) center by a corresponding contact pressure, or that such contact pressure, for pressing the wheel cover onto the wheel body, be applied at two diametrically opposite points in the edge area of the wheel cover. For example, it is particularly reliable if, when pairs of fitting elements are used as securing elements, two such pairs are provided which, viewed over the circumference of the circular wheel cover, are offset by 180° with respect to one another. In this case, these pairs of fitting elements may be designed such that only if the contact pressure for pressing the wheel cover against the wheel body is applied in their area, these fitting elements permit the displacement or displacing movement of the wheel cover required for deactivating the holding device.
In a preferred simple but reliable design of the fitting elements which mutually interact as a securing element according to the invention, one of the fitting elements is constructed in the form of a pin with a rectangular cross-section and the other fitting element is a structure that guides the pin, at least between two mutually opposite sides. Pictorially, this pair of fitting elements can be constructed for this purpose, for example, in the manner of a match box, in which case the interior box part receiving the matches with a rectangular cross-section is connected as a “pin” to the wheel cover and, when the wheel cover is pressed against the wheel body, is inserted into the exterior box shell part, which guides this “pin” as the above-mentioned “structure” and is finally fastened to the wheel body. In this case, it should be noted that neither this structure of the securing element according to the invention, which is finally fastened to the wheel body, nor the second fitting element, which is finally fastened to the wheel body, need not be fastened directly to the wheel body. On the contrary, this second fitting element (or the above-mentioned structure guiding the pin) may be provided on an intermediate element between the wheel cover and the wheel body. The intermediate element, may for example, carry the wheel cover and the pertaining holding device directly, and in turn is appropriately fastened to the wheel body (indicated above in the form of the so-called wheel hub insert illustrated there).
In order not to let the demand on the manufacturing tolerances at the above-mentioned pair of fitting elements grow to extreme proportions, this pair of fitting elements may be designed such that, after a partial displacement of the wheel cover, a more narrow fit will be present. This ensures that in fact only when the wheel cover is pressed completely precisely into the direction of the wheel axis against the wheel body, a free moving position is ensured between these fitting elements. Even when a low diagonal force is introduced, these fitting elements will then hook into one another at this narrowed fit and thereby prevent a further displacement of the wheel cover in a direction releasing the holding device between the wheel cover and the wheel body.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.